One Unit Whole Blood includes the fully patched versions of Blood, Cryptic Passage, and the Plasma Pak, as well as the Blood: Unlock the Secrets guide in a single package.

The game follows the story of Caleb, an undead early 20th century gunslinger seeking revenge against the dark god Tchernobog. It features a number of occult and horror themes. Blood includes large amounts of graphic violence, a large arsenal of weapons ranging from the standard to the bizarre, and numerous enemies and bosses.